Pyrethrin synergist



compositions comprising one or more of the com- 20 liatented Dec. 2, 1947 l 2 431 45 UNITED Y STATES I PATENT OFFICE rranrnn'm smnacrs'r Martin E. Synerholm, Hastings on masons. Y., assignor to Boyce Thompson Institute for Plant Research, Inc., a corporation of New York -No Drawing. Application August 3, 1944, n I

Serial No. 547.983

3 Claims. (01. 167-24) 2 This invention relates to insecticides for cominvention may be formed by condensation of isobating insect pests, such as flies, moths, mosquisafrole and the propyl, butyl, cyclohexyl, benzyl, toes and the like, and has for its object the proor allyl esters of maleic acid, chloromaleic acid,

vision of an improved insecticidal composition. or substitution products thereof, and R in the I have found that compounds having the for- 5 formulae represents groups, the nature of which mulae l depends upon the particular maleic ester used.

\ The synergistic efiect of the compounds is shown 0 cm o in the following table in which the results were 4 CH3 obtained by the Standard Feet-Grady method 0 l and with five-day old flies as described on pages 92 002R com to 98 of Pyrethrum Flowers" by C. B. Gnadinger,

1936 edition, withcompositions comprising com- I II 002R com pounds represented by the formula where R is represented by a radical of the group 7 consisting of propyl, butyl, cyclohexyl, benzyl, and 4 allyl are exceptional synergistic agents in compositions comprising a pyrethrin in a spray me- 0 com. dium, advantageously a mutual solvent. Spray 601R pounds and pyrethrin in a hydrocarbon or minand (L025 pyrethrm W 100 of odorless eral oil, such as odorless kerosene or naphtha. kerosene:

are especially effective insecticides andexhibit strong synergistic phenomena.

The tetrahydronaphthalene derivatives represented by Formula I may be prepared by heating together isosafrole and esters of maleic acid containing the appropriate R group. The use of chloromaleic esters leads to compounds presumably of Formula II.

The aforementioned compounds increase the Ally] toxic eifect of pyrethrins to a very marked extent Cycloiietyl and when they are incorporated in a suitable spraying medium with pyrethrin or like extracts Benzyl the resulting composition has more filling effect against such insects as the ordinary housefly than the combined effects of the pyrethrin and the compound when used alone. The invention The following are the results of tests using 0.025 provides an improved insecticidal composition 8 Pyre rin per 100 ml. of odorless kerosene and comprising one or more compounds of the group 4o't C mpound identified y the formula:

( OTI Adj.PeI R 533 5 53 ggfi Pei-gloat Cent consisting of O CHI O\ g H mo and c i c 5 00,0111.-- 1.0 -95 74 I n a /O CHI where R is a radical of the group consisting of HIC propyl, butyl, cyclohexyl, benzyl, and allyl, and CO:C!HI 0.5 84 as as pyrethrin in a liquid spray medium, for example, of hydrocarbon character, such as odorless OOiCiHi kerosene or naphtha. I claim:

The compounds used in the composition of the '65 1. An insecticidal composition comprising py- 3 v 4 rethrin and a compound represented by the formulae of the group consisting of REFERENCES CITED The following references are of record in the file of this patent:

/ and 0 UNITED STATES PATENTS 0 CH: O 4 C 2 I 0 Number Name Date 001R 7 001R 2,326,350 Gertler et al Aug. 10, 1943 where R is a radical of the group consisting of 10 213621128 ,Gertler et 1944 propyl, butyi, cyclohexyl, benzyl, and allyl.

2. An insecticidal composition according to OTHER REFERENCES claim 1 in which the compound and pyrethrin Hudson at 3.1., Jour. Chem. Soc. 1941, pages are dissolved in kerosene. 715-722. (Copy in Library.)

3. An insecticidal composition according to 15 claim 1 in which the compound and pyrethrin are dissolved in a hydrocarbon solvent.

MARTIN E. SYNERHOLM. 

